The Internet is a global data network that has indeed revolutionized telecommunications. The Internet, however, was not designed for growth, or for providing advanced services requiring global end-to-end broadband connections. The Internet, in its present form, is basically a complex interconnection of primitive nodes called “routers.” The network's structural complexity led to complex routing systems which, in turn, limit the network's capabilities. The global access capacity of the Internet is still in the order of a few terabits per second.
The limitations of the Internet are widely recognized and the network-research community is looking for simple alternatives. The simplification of network structures and network protocols can enable the introduction of advanced services with high performance at low cost. Steps toward providing a simplified network structure are described in the following:                U.S. Pat. No. 6,356,546: “Universal transfer method and network with distributed switch”;        U.S. Pat. No. 6,570,872: “Self-configuring distributed switch”;        U.S. Pat. No. 6,876,649: “High-capacity WDM-TDM packet switch”;        U.S. Pat. No. 6,882,799: “Multi-grained network”;        U.S. Pat. No. 6,920,131: “Global distributed switch”; and        United States Patent Publication No. 20040091264: “Hybrid fine-coarse carrier switching”.        
A wholesale change of the Internet structure to overcome the shortcomings of the present structure is overdue and its realization is facilitated by advances in electronic and optical devices that enable constructing powerful—yet simple—switching/routing nodes of high capacity, spectral multiplexers and demultiplexers, and efficient fiber-optic links for interconnecting such nodes. Advances in fast optical switches enable deployment of optical core nodes of fine granularity thus eliminating the need for optical-to-electronic and electronic-to-optical conversions which are used today in electronic core nodes. There are, however, challenges in optical-core deployment, mainly due to the absence of photonic buffers, at least with the present state of the art. These challenges include timing difficulty, scheduling difficulty, and scalability of fast switching nodes.